/*
 * SSL/TLS interface functions for NSS
 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"
#include <nspr/prtypes.h>
#include <nspr/plarenas.h>
#include <nspr/plhash.h>
#include <nspr/prio.h>
#include <nspr/prclist.h>
#include <nspr/prlock.h>
#include <nspr/prinit.h>
#include <nspr/prerror.h>
#include <nspr/prmem.h>
#include <nss/nss.h>
#include <nss/nssilckt.h>
#include <nss/ssl.h>
#include <nss/pk11func.h>
#include <nss/secerr.h>

#include "common.h"
#include "tls.h"

static int tls_nss_ref_count = 0;

static PRDescIdentity nss_layer_id;


struct tls_connection {
    PRFileDesc *fd;

    int established;
    int verify_peer;
    u8 *push_buf, *pull_buf, *pull_buf_offset;
    size_t push_buf_len, pull_buf_len;
};


static PRStatus nss_io_close(PRFileDesc *fd)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O close");
    return PR_SUCCESS;
}


static PRInt32 nss_io_read(PRFileDesc *fd, void *buf, PRInt32 amount)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O read(%d)", amount);
    return PR_FAILURE;
}


static PRInt32 nss_io_write(PRFileDesc *fd, const void *buf, PRInt32 amount)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O write(%d)", amount);
    return PR_FAILURE;
}


static PRInt32 nss_io_writev(PRFileDesc *fd, const PRIOVec *iov,
        PRInt32 iov_size, PRIntervalTime timeout)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O writev(%d)", iov_size);
    return PR_FAILURE;
}


static PRInt32 nss_io_recv(PRFileDesc *fd, void *buf, PRInt32 amount,
        PRIntn flags, PRIntervalTime timeout)
{
    struct tls_connection *conn = (struct tls_connection *) fd->secret;
    u8 *end;

    wpa_printf(MSG_DEBUG, "NSS: I/O recv(%d)", amount);

    if (conn->pull_buf == NULL) {
        wpa_printf(MSG_DEBUG, "NSS: No data available to be read yet");
        return PR_FAILURE;
    }

    end = conn->pull_buf + conn->pull_buf_len;
    if (end - conn->pull_buf_offset < amount)
        amount = end - conn->pull_buf_offset;
    os_memcpy(buf, conn->pull_buf_offset, amount);
    conn->pull_buf_offset += amount;
    if (conn->pull_buf_offset == end) {
        wpa_printf(MSG_DEBUG, "%s - pull_buf consumed", __func__);
        os_free(conn->pull_buf);
        conn->pull_buf = conn->pull_buf_offset = NULL;
        conn->pull_buf_len = 0;
    } else {
        wpa_printf(MSG_DEBUG, "%s - %lu bytes remaining in pull_buf",
                __func__,
                (unsigned long) (end - conn->pull_buf_offset));
    }
    return amount;
}


static PRInt32 nss_io_send(PRFileDesc *fd, const void *buf, PRInt32 amount,
        PRIntn flags, PRIntervalTime timeout)
{
    struct tls_connection *conn = (struct tls_connection *) fd->secret;
    u8 *nbuf;

    wpa_printf(MSG_DEBUG, "NSS: I/O %s", __func__);
    wpa_hexdump(MSG_MSGDUMP, "NSS: I/O send data", buf, amount);

    nbuf = os_realloc(conn->push_buf, conn->push_buf_len + amount);
    if (nbuf == NULL) {
        wpa_printf(MSG_ERROR, "NSS: Failed to allocate memory for the "
                "data to be sent");
        return PR_FAILURE;
    }
    os_memcpy(nbuf + conn->push_buf_len, buf, amount);
    conn->push_buf = nbuf;
    conn->push_buf_len += amount;

    return amount;
}


static PRInt32 nss_io_recvfrom(PRFileDesc *fd, void *buf, PRInt32 amount,
        PRIntn flags, PRNetAddr *addr,
        PRIntervalTime timeout)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O %s", __func__);
    return PR_FAILURE;
}


static PRInt32 nss_io_sendto(PRFileDesc *fd, const void *buf, PRInt32 amount,
        PRIntn flags, const PRNetAddr *addr,
        PRIntervalTime timeout)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O %s", __func__);
    return PR_FAILURE;
}


static PRStatus nss_io_getpeername(PRFileDesc *fd, PRNetAddr *addr)
{
    wpa_printf(MSG_DEBUG, "NSS: I/O getpeername");

    /*
     * It Looks like NSS only supports IPv4 and IPv6 TCP sockets. Provide a
     * fake IPv4 address to work around this even though we are not really
     * using TCP.
     */
    os_memset(addr, 0, sizeof(*addr));
    addr->inet.family = PR_AF_INET;

    return PR_SUCCESS;
}


static PRStatus nss_io_getsocketoption(PRFileDesc *fd,
        PRSocketOptionData *data)
{
    switch (data->option) {
        case PR_SockOpt_Nonblocking:
            wpa_printf(MSG_DEBUG, "NSS: I/O getsocketoption(Nonblocking)");
            data->value.non_blocking = PR_TRUE;
            return PR_SUCCESS;
        default:
            wpa_printf(MSG_DEBUG, "NSS: I/O getsocketoption(%d)",
                    data->option);
            return PR_FAILURE;
    }
}


static const PRIOMethods nss_io = {
    PR_DESC_LAYERED,
    nss_io_close,
    nss_io_read,
    nss_io_write,
    NULL /* available */,
    NULL /* available64 */,
    NULL /* fsync */,
    NULL /* fseek */,
    NULL /* fseek64 */,
    NULL /* fileinfo */,
    NULL /* fileinfo64 */,
    nss_io_writev,
    NULL /* connect */,
    NULL /* accept */,
    NULL /* bind */,
    NULL /* listen */,
    NULL /* shutdown */,
    nss_io_recv,
    nss_io_send,
    nss_io_recvfrom,
    nss_io_sendto,
    NULL /* poll */,
    NULL /* acceptread */,
    NULL /* transmitfile */,
    NULL /* getsockname */,
    nss_io_getpeername,
    NULL /* reserved_fn_6 */,
    NULL /* reserved_fn_5 */,
    nss_io_getsocketoption,
    NULL /* setsocketoption */,
    NULL /* sendfile */,
    NULL /* connectcontinue */,
    NULL /* reserved_fn_3 */,
    NULL /* reserved_fn_2 */,
    NULL /* reserved_fn_1 */,
    NULL /* reserved_fn_0 */
};


static char * nss_password_cb(PK11SlotInfo *slot, PRBool retry, void *arg)
{
    wpa_printf(MSG_ERROR, "NSS: TODO - %s", __func__);
    return NULL;
}


void * tls_init(const struct tls_config *conf)
{
    char *dir;

    tls_nss_ref_count++;
    if (tls_nss_ref_count > 1)
        return (void *) 1;

    PR_Init(PR_SYSTEM_THREAD, PR_PRIORITY_NORMAL, 1);

    nss_layer_id = PR_GetUniqueIdentity("wpa_supplicant");

    PK11_SetPasswordFunc(nss_password_cb);

    dir = getenv("SSL_DIR");
    if (dir) {
        if (NSS_Init(dir) != SECSuccess) {
            wpa_printf(MSG_ERROR, "NSS: NSS_Init(cert_dir=%s) "
                    "failed", dir);
            return NULL;
        }
    } else {
        if (NSS_NoDB_Init(NULL) != SECSuccess) {
            wpa_printf(MSG_ERROR, "NSS: NSS_NoDB_Init(NULL) "
                    "failed");
            return NULL;
        }
    }

    if (SSL_OptionSetDefault(SSL_V2_COMPATIBLE_HELLO, PR_FALSE) !=
            SECSuccess ||
            SSL_OptionSetDefault(SSL_ENABLE_SSL3, PR_FALSE) != SECSuccess ||
            SSL_OptionSetDefault(SSL_ENABLE_SSL2, PR_FALSE) != SECSuccess ||
            SSL_OptionSetDefault(SSL_ENABLE_TLS, PR_TRUE) != SECSuccess) {
        wpa_printf(MSG_ERROR, "NSS: SSL_OptionSetDefault failed");
        return NULL;
    }

    if (NSS_SetDomesticPolicy() != SECSuccess) {
        wpa_printf(MSG_ERROR, "NSS: NSS_SetDomesticPolicy() failed");
        return NULL;
    }

    return (void *) 1;
}

void tls_deinit(void *ssl_ctx)
{
    tls_nss_ref_count--;
    if (tls_nss_ref_count == 0) {
        if (NSS_Shutdown() != SECSuccess)
            wpa_printf(MSG_ERROR, "NSS: NSS_Shutdown() failed");
    }
}


int tls_get_errors(void *tls_ctx)
{
    return 0;
}


static SECStatus nss_bad_cert_cb(void *arg, PRFileDesc *fd)
{
    struct tls_connection *conn = arg;
    SECStatus res = SECSuccess;
    PRErrorCode err;
    CERTCertificate *cert;
    char *subject, *issuer;

    err = PR_GetError();
    if (IS_SEC_ERROR(err))
        wpa_printf(MSG_DEBUG, "NSS: Bad Server Certificate (sec err "
                "%d)", err - SEC_ERROR_BASE);
    else
        wpa_printf(MSG_DEBUG, "NSS: Bad Server Certificate (err %d)",
                err);
    cert = SSL_PeerCertificate(fd);
    subject = CERT_NameToAscii(&cert->subject);
    issuer = CERT_NameToAscii(&cert->issuer);
    wpa_printf(MSG_DEBUG, "NSS: Peer certificate subject='%s' issuer='%s'",
            subject, issuer);
    CERT_DestroyCertificate(cert);
    PR_Free(subject);
    PR_Free(issuer);
    if (conn->verify_peer)
        res = SECFailure;

    return res;
}


static void nss_handshake_cb(PRFileDesc *fd, void *client_data)
{
    struct tls_connection *conn = client_data;
    wpa_printf(MSG_DEBUG, "NSS: Handshake completed");
    conn->established = 1;
}


struct tls_connection * tls_connection_init(void *tls_ctx)
{
    struct tls_connection *conn;

    conn = os_zalloc(sizeof(*conn));
    if (conn == NULL)
        return NULL;

    conn->fd = PR_CreateIOLayerStub(nss_layer_id, &nss_io);
    if (conn->fd == NULL) {
        os_free(conn);
        return NULL;
    }
    conn->fd->secret = (void *) conn;

    conn->fd = SSL_ImportFD(NULL, conn->fd);
    if (conn->fd == NULL) {
        os_free(conn);
        return NULL;
    }

    if (SSL_OptionSet(conn->fd, SSL_SECURITY, PR_TRUE) != SECSuccess ||
            SSL_OptionSet(conn->fd, SSL_HANDSHAKE_AS_CLIENT, PR_TRUE) !=
            SECSuccess ||
            SSL_OptionSet(conn->fd, SSL_HANDSHAKE_AS_SERVER, PR_FALSE) !=
            SECSuccess ||
            SSL_OptionSet(conn->fd, SSL_ENABLE_TLS, PR_TRUE) != SECSuccess ||
            SSL_BadCertHook(conn->fd, nss_bad_cert_cb, conn) != SECSuccess ||
            SSL_HandshakeCallback(conn->fd, nss_handshake_cb, conn) !=
            SECSuccess) {
        wpa_printf(MSG_ERROR, "NSS: Failed to set options");
        PR_Close(conn->fd);
        os_free(conn);
        return NULL;
    }

    SSL_ResetHandshake(conn->fd, PR_FALSE);

    return conn;
}


void tls_connection_deinit(void *tls_ctx, struct tls_connection *conn)
{
    PR_Close(conn->fd);
    os_free(conn->push_buf);
    os_free(conn->pull_buf);
    os_free(conn);
}


int tls_connection_established(void *tls_ctx, struct tls_connection *conn)
{
    return conn->established;
}


int tls_connection_shutdown(void *tls_ctx, struct tls_connection *conn)
{
    return -1;
}


int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
        const struct tls_connection_params *params)
{
    wpa_printf(MSG_ERROR, "NSS: TODO - %s", __func__);
    return 0;
}


int tls_global_set_params(void *tls_ctx,
        const struct tls_connection_params *params)
{
    return -1;
}


int tls_global_set_verify(void *tls_ctx, int check_crl)
{
    return -1;
}


int tls_connection_set_verify(void *tls_ctx, struct tls_connection *conn,
        int verify_peer)
{
    conn->verify_peer = verify_peer;
    return 0;
}


int tls_connection_set_ia(void *tls_ctx, struct tls_connection *conn,
        int tls_ia)
{
    return -1;
}


int tls_connection_get_keys(void *tls_ctx, struct tls_connection *conn,
        struct tls_keys *keys)
{
    /* NSS does not export master secret or client/server random. */
    return -1;
}


int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
        const char *label, int server_random_first,
        u8 *out, size_t out_len)
{
    if (conn == NULL || server_random_first) {
        wpa_printf(MSG_INFO, "NSS: Unsupported PRF request "
                "(server_random_first=%d)",
                server_random_first);
        return -1;
    }

    if (SSL_ExportKeyingMaterial(conn->fd, label, NULL, 0, out, out_len) !=
            SECSuccess) {
        wpa_printf(MSG_INFO, "NSS: Failed to use TLS extractor "
                "(label='%s' out_len=%d", label, (int) out_len);
        return -1;
    }

    return 0;
}


struct wpabuf * tls_connection_handshake(void *tls_ctx,
        struct tls_connection *conn,
        const struct wpabuf *in_data,
        struct wpabuf **appl_data)
{
    struct wpabuf *out_data;

    wpa_printf(MSG_DEBUG, "NSS: handshake: in_len=%u",
            in_data ? (unsigned int) wpabuf_len(in_data) : 0);

    if (appl_data)
        *appl_data = NULL;

    if (in_data && wpabuf_len(in_data) > 0) {
        if (conn->pull_buf) {
            wpa_printf(MSG_DEBUG, "%s - %lu bytes remaining in "
                    "pull_buf", __func__,
                    (unsigned long) conn->pull_buf_len);
            os_free(conn->pull_buf);
        }
        conn->pull_buf = os_malloc(wpabuf_len(in_data));
        if (conn->pull_buf == NULL)
            return NULL;
        os_memcpy(conn->pull_buf, wpabuf_head(in_data),
                wpabuf_len(in_data));
        conn->pull_buf_offset = conn->pull_buf;
        conn->pull_buf_len = wpabuf_len(in_data);
    }

    SSL_ForceHandshake(conn->fd);

    if (conn->established && conn->push_buf == NULL) {
        /* Need to return something to get final TLS ACK. */
        conn->push_buf = os_malloc(1);
    }

    if (conn->push_buf == NULL)
        return NULL;
    out_data = wpabuf_alloc_ext_data(conn->push_buf, conn->push_buf_len);
    if (out_data == NULL)
        os_free(conn->push_buf);
    conn->push_buf = NULL;
    conn->push_buf_len = 0;
    return out_data;
}


struct wpabuf * tls_connection_server_handshake(void *tls_ctx,
        struct tls_connection *conn,
        const struct wpabuf *in_data,
        struct wpabuf **appl_data)
{
    return NULL;
}


struct wpabuf * tls_connection_encrypt(void *tls_ctx,
        struct tls_connection *conn,
        const struct wpabuf *in_data)
{
    PRInt32 res;
    struct wpabuf *buf;

    wpa_printf(MSG_DEBUG, "NSS: encrypt %d bytes",
            (int) wpabuf_len(in_data));
    res = PR_Send(conn->fd, wpabuf_head(in_data), wpabuf_len(in_data), 0,
            0);
    if (res < 0) {
        wpa_printf(MSG_ERROR, "NSS: Encryption failed");
        return NULL;
    }
    if (conn->push_buf == NULL)
        return NULL;
    buf = wpabuf_alloc_ext_data(conn->push_buf, conn->push_buf_len);
    if (buf == NULL)
        os_free(conn->push_buf);
    conn->push_buf = NULL;
    conn->push_buf_len = 0;
    return buf;
}


struct wpabuf * tls_connection_decrypt(void *tls_ctx,
        struct tls_connection *conn,
        const struct wpabuf *in_data)
{
    PRInt32 res;
    struct wpabuf *out;

    wpa_printf(MSG_DEBUG, "NSS: decrypt %d bytes",
            (int) wpabuf_len(in_data));
    if (conn->pull_buf) {
        wpa_printf(MSG_DEBUG, "%s - %lu bytes remaining in "
                "pull_buf", __func__,
                (unsigned long) conn->pull_buf_len);
        os_free(conn->pull_buf);
    }
    conn->pull_buf = os_malloc(wpabuf_len(in_data));
    if (conn->pull_buf == NULL)
        return NULL;
    os_memcpy(conn->pull_buf, wpabuf_head(in_data), wpabuf_len(in_data));
    conn->pull_buf_offset = conn->pull_buf;
    conn->pull_buf_len = wpabuf_len(in_data);

    /*
     * Even though we try to disable TLS compression, it is possible that
     * this cannot be done with all TLS libraries. Add extra buffer space
     * to handle the possibility of the decrypted data being longer than
     * input data.
     */
    out = wpabuf_alloc((wpabuf_len(in_data) + 500) * 3);
    if (out == NULL)
        return NULL;

    res = PR_Recv(conn->fd, wpabuf_mhead(out), wpabuf_size(out), 0, 0);
    wpa_printf(MSG_DEBUG, "NSS: PR_Recv: %d", res);
    if (res < 0) {
        wpabuf_free(out);
        return NULL;
    }
    wpabuf_put(out, res);

    return out;
}


int tls_connection_resumed(void *tls_ctx, struct tls_connection *conn)
{
    return 0;
}


int tls_connection_set_cipher_list(void *tls_ctx, struct tls_connection *conn,
        u8 *ciphers)
{
    return -1;
}


int tls_get_cipher(void *tls_ctx, struct tls_connection *conn,
        char *buf, size_t buflen)
{
    return -1;
}


int tls_connection_enable_workaround(void *tls_ctx,
        struct tls_connection *conn)
{
    return -1;
}


int tls_connection_client_hello_ext(void *tls_ctx, struct tls_connection *conn,
        int ext_type, const u8 *data,
        size_t data_len)
{
    return -1;
}


int tls_connection_get_failed(void *tls_ctx, struct tls_connection *conn)
{
    return 0;
}


int tls_connection_get_read_alerts(void *tls_ctx, struct tls_connection *conn)
{
    return 0;
}


int tls_connection_get_write_alerts(void *tls_ctx,
        struct tls_connection *conn)
{
    return 0;
}


int tls_connection_get_keyblock_size(void *tls_ctx,
        struct tls_connection *conn)
{
    return -1;
}


unsigned int tls_capabilities(void *tls_ctx)
{
    return 0;
}


struct wpabuf * tls_connection_ia_send_phase_finished(
        void *tls_ctx, struct tls_connection *conn, int final)
{
    return NULL;
}


int tls_connection_ia_final_phase_finished(void *tls_ctx,
        struct tls_connection *conn)
{
    return -1;
}


int tls_connection_ia_permute_inner_secret(void *tls_ctx,
        struct tls_connection *conn,
        const u8 *key, size_t key_len)
{
    return -1;
}


int tls_connection_set_session_ticket_cb(void *tls_ctx,
        struct tls_connection *conn,
        tls_session_ticket_cb cb,
        void *ctx)
{
    return -1;
}
